If you don't accept evolution as the way all critters, including humans, got to be how we are now, stop reading as you won't like what follows. With that housekeeping detail out of the way, let's proceed.
I watched a Nova program on PBS last night that put forward a very interesting hypothesis. It concerns a possible interaction between climate and human evolution.
Paleontologists working in Africa have established that the line of primates which eventually became us diverged from that of the chimpanzees about six million years ago. For a relatively long time our ancestors walked upright but had quite small brains. This was a period when climate was essentially stable in that region of Africa.
Brain size began to increase during a period when the relevant part of Africa experienced climate variability. Geologists decode climate change from sedimentation changes. They say this region went from wet to dry and back several times over what is, in geologic time, a brief period.
The hypothesis is that larger (and smarter) brains became a survival trait during a period when the region in which pre-humans lived experienced relatively rapid shifts from tropical to savanna and back. Smarter pre-humans (with larger brains) were able to cope as conditions changed and adaptation to variable conditions was necessary for survival.
If the hypothesis is correct, modern attempts to suppress climate change - to the extent such attempts are successful - can also suppress our evolution toward becoming even smarter human beings. On the other hand, perhaps we are already smart enough....
